Non-aqueous electrolyte secondary cell

Abstract

The non-aqueous electrolyte secondary cell according to an embodiment of the present disclosure has a positive electrode, a negative electrode, and a non-aqueous electrolytic solution. The negative electrode has a negative electrode collector and a negative electrode active material layer provided on the negative electrode collector. The negative electrode active material layer contains graphite particles A and graphite particles B as negative electrode active materials. The graphite particles A have an internal void rate of 5% or below. The graphite particles B have an internal void rate of 8 to 20%. When the negative electrode active material layer is halved in the thickness direction, a region on the half closer to the outer surface contains more graphite particles A than a region on the half closer to the negative electrode collector.

The invention claimed is: 
     
       1. A non-aqueous electrolyte secondary battery comprising: a positive electrode; a negative electrode; and a non-aqueous electrolyte solution, wherein
 the negative electrode includes a negative electrode current collector and a negative electrode active material layer provided on the negative electrode current collector, 
 the negative electrode active material layer contains graphite particles A and graphite particles B as a negative electrode active material, 
 an internal porosity of the graphite particles A is 5% or less, and an internal porosity of the graphite particles B is 12% to 16%, 
 the graphite particles A are contained more in a half region on an outer surface side of the negative electrode active material layer than in a half region on a negative electrode current collector side of the negative electrode active material layer when the negative electrode active material layer is divided into two equal parts in a thickness direction, and 
 the non-aqueous electrolyte solution contains a Li imide salt. 
 
     
     
       2. The non-aqueous electrolyte secondary battery according to  claim 1 , wherein the Li imide salt contains lithium bis(fluorosulfonyl)imide. 
     
     
       3. The non-aqueous electrolyte secondary battery according to  claim 1 , wherein the negative electrode active material contains a Si-based material.